Present coinventor Mushrush has previously obtained U.S. Pat. No. 3,733,500, issued May 15, 1973 for an Adjustable Electromagnetic Vibrator. A principal use for such a vibrator, as disclosed therein, is for a storage hopper or bin wall in order to assist with movement of stored material to the outlet of the hopper or bin.
Ruckstuhl, U.S. Pat. No. 3,490,705, issued Jan. 20, 1970 shows a hopper-fed hammermill. There is no apparent way of adjusting the radial distance between the hammers and the screen. Throughput is adjusted by damping at 92 the suction being drawn by the fan 66.
In Fritz, U.S. Pat. No. 1,634,026, issued June 28, 1927, throughput is varied by angularly shifting the screen 10 with respect to the screen 8 to put the openings 9 and 11 into greater or lesser registry.
Frickey, U.S. Pat. No. 1,759,448, issued May 20, 1930, shows a rotary grinder fed by a screw conveyor 63. The grinder housing has adjustments at 53 and 23, but they are disclosed as means to permit disassembly, presumably for cleaning.